The present invention relates to a surface covering that is intended to be used on marking coverings for roads, parking areas and the like, and which is designed to give optical directions. To give optical directions, the marking must be visible to the road-users, especially drivers of motor vehicles, and give directions as to how to drive, cycle or walk, or where to park their vehicles.
Road markings of this kind are used in every country where there is a sufficiently high level of traffic, especially vehicular traffic, and where the roads have a solid surface, such as those made of asphalt or concrete. These road markings can have different colors, but are generally white.
Road markings are generally made with thermoplastic materials or similar materials, which are laid on the roadway in the molten state. The marking material is mainly a paint, which can be either water-based or solvent-based. However, multi-component systems, often called cold plastics, are also used. In addition, the marking material can be provided in the form of tapes. These tapes are supplied as xe2x80x9cready-made markingsxe2x80x9d and are fixed to the roadway with the aid of an adhesive layer applied to their underside. The markings can be in the form of continuous lines running along the edge of the road; parallel transverse stripes; continuous or other lines in the middle of the roadway, or arrows indicating the driving direction. Parking areas are also generally provided with such markings. Besides a binder, the marking materials often comprise fillers and light-reflecting beads that make the markings readily visible when light is shone on them in the dark.
These road marking materials can have very different structures and chemical compositions. Examples of such road marking materials are described in U.S. Pat. No. 3,253,146 and British Patent No. 2,043,673. All of the known markings in use are wear-resistant to a certain extent, and after being applied, they can withstand the load to which they are subjected e.g. by the wheels of vehicles.
In the case of flat road markings, the light-reflecting glass beads lie below the surface for the greater part of their size. In dry weather, the light beam of a car impinges on the upper part of these glass beads, and the light is reflected back from the rear inside surface of the beads, so that the beads and the road marking can be easily seen. In damp weather or rain, however, a film or layer of water is formed on these beads, as a result of which the light is not reflected back, but is deflected in the direction of the light beam. In such a case, the road marking cannot be readily seen, and its efficiency in the dark in difficult conditions may be reduced by 80 to 90% in comparison with its efficiency under dry conditions. It is therefore desirable to somehow raise the glass beads above the surface, so that they lie above the layer of water. However, the problem with this solution is that the beads are then subject to excessive wear and tear, caused especially by studded tires, while snowplowsxe2x80x94where usedxe2x80x94can simply shave the projecting beads off. The situation is the same with the transverse stripes, where the road markings between the stripes are completely invisible in damp weather. If the beads are arranged on a firm base, and project up between these stripes, they are again quickly worn off by the wheels of vehicles, especially if these are fitted with studs, and they are also shaved off by snowplows.
In accordance with the present invention, these and other objects have now been realized by the invention of surface coverings for use in marking a road surface comprising elastic particles for application to the road surface, the elastic particles including a plurality of light reflecting members including glass beads and/or ceramic particles. In a preferred embodiment, the elastic particles include pigments. Preferably the pigments include pigments such as fluorescent pigments, phosphorescent pigments and/or color pigments.
In accordance with one embodiment of the surface coverings of the present invention, the elastic particles comprise an elastic material such as elastomers or thermoplastic elastomers. In a preferred embodiment, the elastomers include natural rubber, styrene rubber, chloroprene rubber, ethylene propylene diene monomer rubber, nitrile rubber, fluorocarbon rubber, silicone rubber and/or polyurethane rubber.
In accordance with another embodiment of the surface coverings of the present invention, the thermoplastic elastomers include styrene isoprene styrene rubber, styrene butadiene styrene rubber, ethylene vinyl acetate copolymer, thermoplastic olefins, thermoplastic urethanes, polyesters, polyethers, and/or polyamides.
In accordance with another embodiment of the surface coverings of the present invention, the surface covering comprises a monolayer of the elastic particles.
In accordance with another embodiment of the surface coverings of the present invention, the surface covering comprises multiple layers of the elastic particles.
In accordance with another embodiment of the surface coverings of the present invention, the elastic particles have a shape such a spherical, conical, rod-shaped, rhomboidal or cubic shapes.
In accordance with a preferred embodiment of the surface coverings of the present invention, the elastic particles have a size of between 0.5 mm and 20 mm.
The need to solve the above problems have long been felt, and the aim of the present invention is therefore to provide a surface covering which is intended to be used on marking coverings for roads, parking areas and the like, characterized in that it consists of elastic particles comprising light-reflecting glass beads or ceramics.
The surface covering according to the present invention suitably comprises one or more pigments, possibly including fluorescent and/or phosphorescent ones, and pigments that confer color and covering ability on it.
Besides the glass beads or ceramics, the particles according to the present invention suitably consist mainly of elastomers, such as natural rubber, styrene rubber, chloroprene rubber, ethylene propylene diene monomer (EPDM) rubber, nitrile rubber, fluorocarbon rubber, silicone rubber or polyurethane rubber, or of thermoplastic elastomers, such as styrene-isoprene-styrene (SIS) rubber, styrene butadiene-styrene (SBS) rubber, ethylene-vinyl acetate copolymer (EVA), thermoplastic olefins, thermoplastic urethanes, polyesters, polyethers, polyamides, and/or mixtures of these.
Furthermore, the surface covering according to the present invention suitably consists of particles forming a single particle layer (monolayer).
The particles according to the present invention are suitably spherical, conical, rod-shaped, rhomboidal or cubic in shape.
The particles according to the present invention should have a size of between 0.5 mm and 20 mm.